the comment below you can tell
tldr: the items with not the exact same decay value (you cant see it by default) don't stack

I just started a new vanilla game and this didn't work.

I just tested this and it works perfectly fine. Regarding decay; so long as the item in question was created at the same time, and therefor has the same time of decay, it will stack.

E.g. Five Baked Potato with 2hr 30m of decay timer left will stack, a sixth Baked Potato with 1hr 10m decay timer left will only stack with other Baked Potato of the same decay.

To me, that is working exactly as one would expect.

i only cared about the stack
idk about decay, its probably the exact same as 1 food item

maybe if decay becomes a big issue i'll make a update to the mod that changes the food decay functionality

Main reason for unstackable food is decay.
How does this mod handle food decay?